Conventional crimping tools have different kinematics and mechanics for their activation:
A first embodiment of crimping pliers of the applicant of the present patent application, see German Patent No. DE 37 08 727 C2 corresponding to U.S. Pat. No. 4,794,780, German Patent No. DE 197 53 436 C2 and German Patent No. DE 198 02 287 C1 corresponding to U.S. Pat. No. 6,053,025, uses hand levers and crimping jaws, wherein these hand levers and crimping jaws are pivoted in a common plane. The crimping jaws are pivoted with respect to a pivoting axis having an orientation perpendicular to the aforementioned plane. In an open state of the crimping pliers the crimping jaws build an opening angle so that it is possible to introduce a work piece into the head of the pliers built with the crimping jaws. Each crimping jaw supports a plurality of halves of nests. The halves of the nests are located one behind another in radial direction from the pivoting axis. Pairs of halves of the nests build a nest, wherein each nest has a contour correlating with the crimped contour of the work piece in a closed state of the crimping pliers. With a pivoting closing movement of the hand levers and the crimping jaws the halves of the nests get closer to each other and finally reach their closing position. According to German patent No. DE 37 08 727 C2, the halves of the nests are directly formed in the crimping jaws. Instead German Patents Nos. DE 197 53 436 C2 and DE 198 02 287 C1 disclose inserts, wherein a plurality of halves of nests is built in each insert. The inserts are separate from the crimping jaws and are exchangeably mounted with the crimping jaws.
Also for another embodiment of the applicant of the present patent application, see German Patent No. DE 40 23 337 C1 corresponding to U.S. Pat. No. 5,153,984, German Patent No. DE 44 27 553 C2, German Patent No. DE 198 32 884 C1 corresponding to U.S. Pat. No. 6,155,095, German Patent No. DE 100 56 900 C1 corresponding to U.S. Pat. No. 6,612,147, German Patent No. DE 101 32 413 C2 corresponding to U.S. Pat. No. 6,877,228, German Patent No. DE 101 40 270 B4, the hand levers and the crimping jaws move in a common plane. However, for these embodiments the pivoting relative movement of the hand levers is converted by a transfer mechanism into a translational movement of the crimping jaws. For these embodiments, the head comprises one fixed crimping jaw and one movable crimping jaw, wherein the movable crimping jaw has a translational degree of freedom versus the fixed crimping jaw along the longitudinal axis of the crimping pliers. Also for these embodiments the crimping jaws each comprise a plurality of halves of nests. Accordingly without any reconstruction or exchange of parts one and the same head might be used for crimping work pieces with different cross-sections and contours. For these embodiments the plurality of halves of the nests are positioned one besides another in transverse direction to the crimping axis, so in transverse direction to the translational degree of freedom of the movable crimping jaw. The head of the pliers is built with an O-shaped frame, wherein the upper transverse leg of the O-shaped frame correlates with the fixed crimping jaw. The movable crimping jaw is guided within the O-shaped frame for the translational movement along the side legs of the O.
Another embodiment is known from German Patent No. DE 197 13 580 C2 corresponding to U.S. Pat. No. 5,913,933, German Patent No. DE 198 07 737 C2 corresponding to U.S. Pat. No. 6,026,671, German “Gebrauchsmuster” DE 298 03 336 U1, German Patent No. DE 102 42 345 B3 corresponding to U.S. Pat. No. 6,910,363 and German Patent No. DE 197 53 436 C2. Here a movable crimping jaw comprising a plurality of halves of nests is moved along a translational degree of freedom versus a fixed crimping jaw. However, for this embodiment the head comprises a C-shaped frame, wherein the upper transverse leg of the C is fixedly connected with a fixed crimping jaw or a fixed insert.
Further embodiments of crimping pliers are known from German Patent Application No. DE 197 09 639 A1, German Patent No. DE 198 34 859 C2, German Patent No. DE 199 24 086 C2 corresponding to U.S. Pat. No. 6,286,358, German Patent No. DE 199 24 087 C2 corresponding to U.S. Pat. No. 6,289,712, German Patent No. DE 199 63 097 C1 corresponding to U.S. Pat. No. 6,474,130, German Patent No. DE 103 46 241 B3 corresponding to U.S. Pat. No. 7,155,954 and German Patent Application No. DE 10 2007 001 235 A1 corresponding to US Patent Application No. US 2008/0163664 A1. Here, the head of the pliers is used for crimping a fitting for tubes or sanitary systems. Also for these pliers the crimping jaws are pivoted with respect to a pivoting axis. However, these crimping jaws only have one single half of a nest for a fitting having a particular geometry.
Furthermore, German Patent No. DE 40 26 332 C2 corresponding to European Patent No. EP 0 471 977 B1 and German Patent No. DE 40 39 435 C1 corresponding to U.S. Pat. No. 5,187,968 of the applicant of the present patent application disclose crimping pliers having a nest being built at the front region of the head of the pliers. For these embodiments the work piece is introduced in longitudinal direction of the crimping pliers into the front region of the crimping pliers.
Furthermore, there are crimping tools, wherein the head of the crimping tool is not manually activated but activated by an external source, e.g. an electrical or hydraulic unit.
Also German “Gebrauchsmuster” No. DE 201 00 031 U1 discloses crimping pliers of the above mentioned type having crimping jaws pivoted around a pivoting axis. The crimping jaws hold exchangeable inserts each having a plurality of halves of nests with different contours and cross-sections. The crimping jaws have guiding protrusions used for guiding the inserts. In an operational position of the inserts such operational position is fixed by means of a resting sphere biased by a resting spring. In the operational position the resting sphere engages a resting groove of the inserts. One tool set is built with one crimping jaw and a plurality of inserts having halves of nests with differing geometries. The document cites background art with a case housing both the crimping pliers and the plurality of inserts. Instead DE 201 00 031 U1 suggests holding the inserts at the inner sides of the hand levers of the crimping tools and storing the inserts held by the hand levers until an exchange of the inserts for another work piece becomes necessary.
European Patent Application No. EP 1 231 027 A2 discloses a head for a crimping unit for connecting tubes. Here, the inserts activated throughout the crimping movement directly build the contact surfaces with the work piece. However, the document also suggests providing dove tale connections at the inserts for positively locking crimping jaws, wherein the inserts are fixed in their single operating state by a spring biased latching body. Furthermore, it is suggested both using contact surfaces for axially pressing the fitting and contact forces for radially pressing a fitting. Furthermore, the document suggests inserting the inserts in two orientations into the dove tale guidances.
German Patent No. DE 196 28 752 B4 (corresponding to U.S. Pat. No. 5,802,908) mentions as prior art German Patent No. DE 28 41 588 C3, German “Gebrauchsmuster” No. DE 19 58 830 U and German “Gebrauchsmuster” DE 86 04 624 U1 using a pair of rotatably supported crimping matrices in the shape of profiled wheels. The profiled wheels have at their periphery a plurality of halves of nests with differing geometries. The maximum number of halves of the nests with differing geometries is limited by the maximum diameter of the profiled wheel. In one single operating state the profiled wheels are locked by means of a spring biased bolt engaging the outer circumference of the profiled wheels. In modification of such background art, document DE 196 28 752 B4 suggests pivotably linking two separate rotatable crimping matrices with each of the crimping jaws. Such modification doubles the number of the halves of nests provided with one and the same crimping tool.
German Patent No. DE 41 17 305 C2 corresponding to U.S. Pat. No. 5,228,325 discloses crimping pliers having an upper die and a lower die, wherein the dies are rotatably supported by the crimping jaws with a rotational degree of freedom having an orientation parallel to the crimping axis.